A base station apparatus (a base station, a cell, a first communication apparatus (communication apparatus different from a terminal device), and eNodeB) and a terminal device (a terminal, a mobile terminal, a mobile station apparatus, a second communication apparatus (communication apparatus different from the base station apparatus), user equipment (UE), and a user device), which are included in a communication system such as Wideband Code Division Multiple Access (WCDMA) (registered trademark), Long Term Evolution (LTE), and LTE-Advanced (LTE-A) by Third Generation Partnership Project (3GPP) (registered trademark), and a Wireless Local Area Network (WLAN), and Worldwide Interoperability for Microwave Access (WiMAX) (registered trademark) by The Institute of Electrical and Electronics engineers (IEEE) (registered trademark), realize high-speed data communication by including a plurality of transmit and receive antennas and performing spatial multiplexing on data signals using a Multi Input Multi Output (MIMO) technology.
In 3GPP, in order to realize high-speed data communication between the base station apparatus and the terminal device, carrier aggregation (CA) in which simultaneous communication is performed by using a plurality of component carriers has been employed (NPL 1).
In 3GPP, as a frame structure type of a bi-directional communication scheme (duplex communication scheme), frequency division duplex (FDD) and time division duplex (TDD) has been employed. In FDD, a full duplex scheme in which bi-directional communication is able to be simultaneously performed, and a half duplex scheme in which the bi-directional communication is realized by switching uni-directional communication have been employed (NPL 2). LTE that employs the TDD may be referred to as TD-LTE or LTE TDD.
In 3GPP, TDD-FDD carrier aggregation (TDD-FDD CA) in which communication is performed by aggregating a component carrier (TDD carrier) which supports the TDD and a component carrier (FDD carrier) which supports the FDD has been examined (NPL 3).